Ghosts of London
by Hekate1308
Summary: The fog came suddenly, but not unexpected. Written for a tumblr challenge.


**Author's note: The Let's Write Sherlock challenge on tumblr this month was writing a creepy story, and how could I resist?**

**Enjoy!**

The fog came suddenly, but not unexpected. Until that day early in October, it had been a very warm and clear autumn; but London fog often appeared when one least expected it, and despite the street lights, it still laid an impenetrable darkness over the town.

John had been out to buy groceries when the fog descended and was now groping his way along the wall of the building next to 221B.

When someone grasped his arm, he tried to shake him off, but realized at the annoyed hiss that it was Sherlock.

"This way" he ordered and pulled John with him.

He was strangely glad to be back at the flat, far gladder than he could explain with being out of the fog; he stood for a moment dumbfounded, only shaking himself out of it when Sherlock took the bags from his hand. He had never done that before.

Mrs. Hudson came to see what they were doing. She had heard that they hadn't gone upstairs.

"Is everything alright?"

"Yes, Mrs. Hudson" Sherlock replied, "We were just – " he stopped and took the first few steps, then stood still and continued, "You're not planning on going out?"

Mrs. Hudson shook her head.

"No, dear. It's too late and the fog's too thick for me."

But Sherlock was already dragging John up, without waiting for her explanation.

"Sherlock?" he asked, still confused.

Once they were in the flat he realized he had no reason to be. He shook his head, trying to clear it.

"The fog" Sherlock said, moving into the kitchen.

"What?" John inquired, right before Sherlock came back with a syringe in his hands.

"What are you – "

"I need a blood sample."

"What?" he demanded.

Sherlock stood in front of him, looking calm as always. He should have expected it; they hadn't had a case in weeks; his best friend was bored, of course. Letting him draw his blood was certainly far less inconvenient than some of Sherlock's other distractions and he gave him the sample before moving to open a window. The air in the flat felt strangely stale.

Right as he was about to open one in their living room, Sherlock grabbed his arm and dragged him back.

"What are you doing?" John demanded, tearing himself free.

"Can't you see?" Sherlock asked, the syringe still in his hand. He gesticulated towards the window. "Can't you _see_?"

"What am I supposed to see?" John snapped back before he realized that he was angry at Sherlock without knowing why. He was behaving strangely, but that was hardly out of the ordinary. And he had been in a good mood when he had returned.

"Describe the fog to me".

Sherlock's voice calmed him down and, feeling guilty for having snapped at his friend, he looked out of the window.

"It's – fog" he finally said.

"Correct, but I was hoping that you could go into more detail".

"I don't know what you want me to say. It's normal, dense, thick –" John stopped. There was something strange about that. The fog had been dense when he had returned, but not this dense. It looked almost solid.

Sherlock nodded as if he had proved something and went into the kitchen.

John followed him and watched as he processed his blood sample.

"You left the window in your room open when you left" Sherlock informed him while he was working. "I was cataloguing my mind palace when I realized my thought processes were growing clumsy. I noticed that fog had drifted into the flat and that it simply stayed."

"Stayed?"

"In the same form it had been when it came in".

John had no idea what he was talking about, but Sherlock was serious, and he decided to wait until he had finished the test. He sat down with a book but found that his eyes were drawn to the window more often than to the page he was reading. There was something about this fog... Now he wondered why he hadn't noticed while he had been walking home. It was strange, was it not, how it had suddenly descended? And how thick it was?

He heard a knock from the kitchen that he recognized as Sherlock slamming his hands on the table in frustration.

"Nothing!" His friend strode into the living room.

"But maybe it is" John argued. "That would be good news, wouldn't it?"

Sherlock shot him a look that told him how idiotic he thought his statement. "Do you think your confusion when you came in was nothing? Or the fact that it is getting darker as we speak?"

It was true. Night had fallen, but the darkness was becoming impenetrable.

Someone rang the doorbell and Sherlock immediately bolted down, calling out to Mrs. Hudson that he was opening the door.

John was definitely worried now.

But it was nothing to what he felt in comparison when Greg entered the flat. He was pale and his gaze strangely unfocused; his eyes kept wandering from Sherlock to John to the windows and back again.

"Greg?"

He looked at John and blinked. "Yes?" he asked finally.

If he had been in this state when he'd returned from shopping, he understood Sherlock's reaction.

He made him sit down on the sofa and made tea while Sherlock took a blood sample. When he returned with the cuppa, the consulting detective was still sitting next to the DI, obviously reluctant to leave him alone.

"He barely flinched" he informed him, holding up the syringe. John frowned.

"I'll stay" he said immediately and Sherlock left to do the same test on Greg's blood that he'd done on John's, with the same result.

By this time, the DI was acting more like himself.

"I – what's going on?" he shook his head. "This is – right. There's a case."

"Not right now, Greg" Sherlock answered, pacing up and down the room.

"What?" he exclaimed. "Since when don't you want to hear about a case?"

"Since the fog" Sherlock answered matter-of-factly.

"The fog?" Greg looked out the window. "It's rather thick" he commented.

Sherlock rolled his eyes. "And did you notice anything unusual about it?"

"What do you mean?"

"What it did to you, for example".

Before Sherlock could continue, John explained, "You were confused when you came in."

"I – " Greg stopped and thought about it. "You're right. You think this has something to do with the fog?"

"When it appeared my thought processes became slower" Sherlock said, "and John's return confirmed it".

The DI looked at John, who nodded. He stood up and walked to the window, but made no move to open it.

"So you think the fog..." he trailed off.

"It's likely" Sherlock said calmly.

Suddenly, Greg staggered back, his eyes wide open.

"Greg?" John asked, jumping up.

"It's just – that explains a lot. A body was found an hour ago. At the crime scene, everyone was acting strange. I didn't think so at the time, but I could barely think a coherent thought, so it's no surprise I didn't notice. Body's at the morgue".

"Already?" Sherlock inquired.

"It didn't seem there was much to go on – what's this fog doing to us?" Greg shook his head. "I even came here instead of texting you".

"It's good you did" Sherlock informed him, getting his coat.

"Where are you going?"

"To the morgue".

"To the morgue? Through the fog?" John demanded.

"There is no other way".

"I'm coming with you".

"I do not see why we both need to expose – "

"We three" Greg corrected him.

"You –" John tried to argue, but the DI was already standing up, and he knew he could be as stubborn as Sherlock when he chose to.

Sherlock strode out of the flat and down the stairs. John and Greg followed and found him knocking on Mrs. Hudson's door.

"Yes, dear?" she asked.

"Promise me you won't go out" he said immediately.

"Don't worry. I won't be going out tonight, or tomorrow, if it stays like that. I don't like the fog. It's..." she searched for a word and gave up. "I'll wait until it clears. Or until I run out of groceries".

"Call me. I can arrange with Mycroft to have them brought here".

"That's really not necessary – "

"Mrs. Hudson". The pleading tone in his voice was enough for their landlady, who smiled and promised she would stay in and keep her windows closed.

Sherlock went to the front door and turned to face John and Greg.

"Take slow breaths" he instructed them "and try to stay focused. I will do my best to get a cab as quickly as possible".

Of course he did so immediately, before they could even get dizzy.

"Tell me about the case" Sherlock ordered as soon as they were seated.

"Male in his late twenties, no apparent injuries. He looked like he fell down and died. But..."

"But?"

Greg struggled for words.

"His face looked – hollow. I don't meant that he didn't eat enough, I mean that his expression – I have seen many dead bodies. But something was – missing".

Normally Sherlock would have demanded that he explain himself better, but he didn't say a word. He continued to look at the fog, frowning.

John had never seen such an expression on his face, and he had thought that he knew them all. What was going on in Sherlock's mind? And what was the fog doing? Was it really doing anything or were they going insane? Then again, most people would assume that they already were.

Neither he nor Greg said anything. They didn't want to disturb Sherlock while he was undoubtedly going through his mind palace.

Molly awaited them at the morgue; she already had the body ready.

Greg had been right.

John had seen countless bodies. During his studies, his time in the army and as Sherlock's best friend. But this –

This was not the tranquillity of death. This was a lack of everything. It was more believable that a doll lay before them than that the man had ever been alive at all.

Sherlock immediately began his examination.

"Sells technical equipment, single, lives alone. Lifeless".

He stopped, realizing what he had just said, but John decided that it was the best description he could have come up with.

He had never seen a more lifeless dead body, as insane as it sounded.

"He hasn't yet been prepared for the autopsy..." Sherlock said. Molly looked at him.

"I tried, but – " She stopped. She didn't have to explain. John felt it too; the reluctance to go near the body. Sherlock was the only one who had come close, even though the doctor usually examined the bodies because his friend wanted him to.

He took a step forward, then another. Finally he arrived at the body.

It felt like he had taken much longer than the few seconds he'd needed.

"I see no injuries on him" he said. "He's – "

He stopped.

"When was the body found?"

Sherlock looked at him. He had noticed too that the rigor mortis was far advanced. He must have been dead for hours.

"Two hours ago" Greg answered. "And a man who lives nearby swears he walked down the pavement not half an hour before that and there wasn't a body there".

"So he was dropped there?" John asked. But it didn't seem plausible. The man's clothing was undisturbed. Nothing showed that he had been carried or dragged.

"Maybe not" Sherlock replied.

"What other option is there?"

Sherlock didn't answer. He was turning the man's right hand around.

"Interesting" he murmured. "John, wouldn't you say he feels strange?"

It was a weird thing to say, even for Sherlock, but once more the doctor found he agreed. Even through the latex gloves, he could tell that the man's skin felt like it was made out of wax.

But this was a real body. And yet he seemed so unreal...

"What is going on here?"

Greg voiced what they all thought.

"I don't know".

Sherlock said it calmly, without paying attention to the looks they threw him.

John had never seen him so grave, not even before he had faked his suicide.

"Molly, we need to do the autopsy immediately".

By this time, the pathologist had got over the revulsion the body inspired and immediately began to strip it.

Greg went to get coffee while they examined the corpse.

It was a mystery. After two hours, they had found nothing that could have killed the man. There were no injuries; no signs of damaged organs; Sherlock took some of his blood to check for poison but he was not optimistic.

The victim had ceased to live. It was as simple as that.

While Sherlock and Molly were testing the blood, Greg asked, "Have you ever seen something like that? A body like that?"

"No" John replied. "And Sherlock hasn't either". He would already have told them.

Greg sighed. "It was one of the reasons we brought the body into the morgue so quickly. Not just the confusion, but – no one could stand to look at it. We were glad when it was gone".

His phone rang. He looked at the caller ID and sent John an expressive look. One he had seen too often not to know the meaning of.

Another body.

Greg left the lab to take the call, and John saw Sherlock's eyes following the DI. The consulting detective knew too.

When Greg returned, he inquired, "Another one?"

"Four" he informed him tensely.

Sherlock nodded. "Molly, finish the tests".

John only understood what he was about to do when he took his coat.

"Sherlock..." he began, then broke off.

He didn't know what to say.

He couldn't stand the thought of Sherlock exposing himself to the fog. Him or Greg being confused was one thing; it was clear that the effect wasn't permanent; but Sherlock, struggling to keep his mind, even for a second, was not something he could bear. Sherlock prided himself on his intellect, Sherlock had often said that he would be nothing without his mind, and John wouldn't allow him to lose it even for a second.

"I have to see the bodies" Sherlock said, "or one, at least".

He wasn't pleading; he wasn't telling John that he would go no matter what he said, despite it being true; he was telling his friend that he would go no matter what, but that he wanted him to understand. John did and got his jacket.

Sherlock smiled.

"Molly, we'll be back soon".

"Be careful" she said softly, and they left.

They decided to go to the nearest body. It had been found not half an hour from St. Bart's, and they quickly stepped into the car that had been sent for them.

The fog looked thicker than ever, and John fancied that it had become more difficult to breathe, but it could be his imagination.

It was another young man, and Greg told them that the other victims were young too.

John took slow, even breaths, but it didn't help much. He was soon dizzy and confused again, having to remind himself why he was here in the first place.

But he noticed that the younger PCs and forensic techs became strangely listless the longer they stayed in the fog. Men and women who were older – at least older than thirty, he decided – were as confused as he and Greg and Sherlock; but younger ones seemed to wait for someone, to peer into the darkness.

He was about to ask them what was going on when Sherlock stood up, his face grim, and dragged them to the nearest police car.

He drove back to St. Bart's, Greg and John recuperating in the back seat.

He didn't say anything until they were back in the lab and Molly confirmed that the blood tests had revealed nothing.

Sherlock strolled into another room, John and Greg following.

"Sherlock? I know you have a theory" John prompted. He was used to wait, but the consulting detective hadn't said a word in over half an hour, and he was starting to worry.

His friend looked at him, and John saw something he had rarely noticed in Sherlock's behaviour. Hesitation.

"Do you know" he began "the old German word for "dead"?"

"Doesn't "tot" mean dead?" Greg asked. Sherlock nodded.

"That's not what I meant, though. The old German word is _entseelt_".

"Entseelt?" John repeated, his pronunciation to nearly as perfect as Sherlock's.

"Literally, it means un-souled" he explained, wincing at having to use a made-up word. "I think that is what is happening".

"Wait" Greg said, "are you suggesting this people died because their soul was taken from them?"

Sherlock looked at him.

"Their soul. As in, the part that goes to Heaven, soul?"

"Yes".

"But the _soul_" John interjected and as always, Sherlock guessed what he was about to say.

"I do admit that the existence of the soul, of an immaterial spark of life that animated a body, has never been scientifically proven" he said. "But neither has it been disproved".

And Sherlock hadn't wanted to theorize without data, John realized. He had not thought about the existence of the soul because he could find nothing to make him sure. And because of that, he had developed a theory that no one else would have considered possible.

"It would explain the different reactions to the fog" the consulting detective continued.

"You mean that young people just stare?" Greg inquired.

"I assume the soul is best consumed when it is not yet burdened" Sherlock answered simply.

He glanced at John. The doctor understood.

In years, they weren't much older than the victims – except for Greg, who had turned fifty-two a few months ago – but they had lived through much more. John had fought in a war, and Sherlock –

In a way, he had done the same, he supposed.

"You said yourself there was something missing" Sherlock told Greg, and John realized that the DI was the only one who doubted the explanation.

John had too often seen the light in a man's eyes extinguished not to believe in the soul; and those bodies – something had been ripped from them.

Greg looked from Sherlock to John and back again.

"You're right" he finally said. "God help me, but you're right. What do we do?"

"We don't know what we are up against" Sherlock answered. "We have to find out who's stealing people's souls".

"Do you think it's... ghosts?" Greg asked.

"It's possible. I have never given much thought to ghost stories and legends".

He took his phone out and called Mycroft.

"I need all the information about urban legends and supernatural happenings in London that you can find" he said when his brother picked up. There was no need to explain. Mycroft would know what was going on.

"You will receive e-mails, and I will send books" his brother replied. Neither of them bothered to mention that Sherlock was at St. Bart's.

"Do you have a number?"

"Twelve confirmed deaths. One of them was working in the Ministry of Inner Affairs".

Sherlock hoped Mycroft could keep the Secret Service away from the case. It would only complicate matters.

The books arrived shortly afterwards. Sherlock was already busy with the e-mails. John took care of the man who brought them and staggered as he walked into the lab.

The effect of the fog was growing stronger. He couldn't have been exposed long.

He mentioned this to Sherlock, who nodded and continued his research. John and Greg grabbed a book too and did their best to ignore the tell-tale sounds that occasionally emitted from the corridor – that confirmed that another body had come in. Sometimes, they heard Molly speak too.

"Is the fog getting worse?" she asked gently after the fifth body.

"It's getting thicker and thicker" a woman answered.

They kept reading.

Eventually Greg exclaimed, "I found something! It says that ghosts scare humans to drink the life out of their soul wounds. It's not exactly the same, but – "

"It's legends. It's close enough" Sherlock said immediately.

"Ghosts are feeding on the living?" John asked.

"It would seem so".

"But how?"

Sherlock didn't answer. Instead, he tried to come up with a theory why people were attacked on this day.

"There are many variables" he muttered to himself. "Obviously this hasn't happened before, or we would know about it. So there has to be something... It's Friday, the 13th October. It's new moon. Maybe the temperature..." he threw the book away.

"This leads us nowhere. We have to know how to fight them".

He called Mycroft.

"Is there a pattern?"

"There seems to be a centre" Mycroft said. "All deaths took place within seven miles of one point. The London stone".

Sherlock hung up without saying a word and repeated Mycroft's words.

"The London stone? In Cannon Street?" Greg asked.

"It has long been rumoured that there was a certain occult significance attached to it" Sherlock explained. "If we only knew how..."

He stopped and then said, "We have to destroy it".

"Destroy a landmark of the town that has been around for hundreds of years?" John exclaimed.

"Do you want the town to still be there in the morning?" Sherlock answered.

"Is there no other way?" Greg asked.

Sherlock looked sceptical. "There's a cleaning ritual we could try – it appears to be of Celtic origin – "

"Let's try" John said. "We can still destroy it if it doesn't work".

Sherlock acquiesced.

"We need to burn certain woods..." he remarked, looking over the ritual in an old book that he hadn't allowed them to touch and that, as far as John could tell, was written in Gallic.

After another call to Mycroft, they soon had the necessary ingredients.

Sherlock closed the book and took the bag. He looked at them.

John guessed what he wanted to say.

"No".

"You cannot help me. I have to burn the wood, I have to recite the spell. You cannot keep the ghosts away. You will only put yourself in danger. You are not coming".

"Then you are not going" the doctor said simply, the DI agreeing with him.

Sherlock wanted to protest, but another text informing him that there were now more than fifty victims changed his mind. The three left the hospital.

It was surprisingly easy to breathe. With the fog, John would have thought it almost impossible, but it wasn't. It was logical, though; if one could breathe, one could breathe the fog in.

A car Mycroft had sent was already waiting for them.

Luckily, they only saw a few people on the street, and Sherlock deduced that they were too old.

They arrived at Cannon Street and all but ran to the Stone. John had passed it many times but never paid it much attention. It looked completely normal.

Sherlock quickly opened the lock of the grate that protected it from the dangers of day-to-day traffic and started working.

John didn't really know what he was doing, but he didn't care.

Then he realized what he had just thought and stared at Greg, who was shaking his head, mumbling to himself to remember something.

"Greg?"

The DI looked at him.

"Do you feel – "

"Listless? Yes" John said, panic washing over him despite his strange reluctance to take part in the proceedings.

The ghosts knew and they were feeding on their souls.

Even Sherlock's movements were becoming slower and slower.

John noticed Greg starting to sway and grabbed him.

"Sherlock!"

The consulting detective began working faster again, but with John having to support Greg, whose face grew more like a mask with each passing second, it was difficult to concentrate.

He was getting dizzy.

The fog began taking shape now, strange beings he couldn't identify swimming by in front of his eyes, but he didn't know if it was real or if he was hallucinating.

Sherlock called out, but John only understood "Me" before anything went dark. He thought he saw a flame, but he couldn't be sure.

"John?" Sherlock was shaking him. He opened his eyes. Sherlock looked down at him, relief in his eyes.

The fog was gone.

"Greg – "

"He's fine" Sherlock said, prompting a grumble from the DI who was lying next to John.

"How long was I out for?"

"Two minutes".

"The fog is gone".

"It was gone the moment I finished the ritual".

"So it's over?"

"Yes. Can you stand up?"

They managed with some help from the consulting detective and returned to Baker Street in Mycroft's car. "So" Greg began once they were seated in front of the fireplace, a glass of brandy in hand, "We just saved the city?"

Sherlock nodded.

"So there's not only killers but ghosts too".

Sherlock didn't answer.

"What did you call out when you were doing the ritual?" John asked suddenly. He had almost forgotten about it until they had arrived home.

"I told them to take me" Sherlock said simply, staring in the fire.

John and Greg looked at one another. They knew better than to comment on it and simply kept him company in the knowledge that he valued their friendship as much as they his.

It was John who broke the silence fifteen minutes later.

"What happens if they come back? Or if others appear?"

"We deal with them" was the answer.

And, John found, it was the only answer he needed.


End file.
